Efficient Vertical Handoffs in Wireless Overlay Networks

Mobile IP is used to keep track of location information and make the data available to the mobile device anytime, anywhere. It is designed to address the macro-mobility management, it does not address micro-level mobility issues such as handoff latency and packet loss. In this paper, we propose a mobility management scheme to handle the movements of mobile nodes among different wireless network technologies. Our scheme combines: (a) A hierarchical mobility management architecture to hide mobility of mobile nodes within the foreign domain from the home agent; (b) A handoff protocol to reduce packet loss during the transition from one cell to another; (c) The use of our proposed virtual cells in order to reduce the upward vertical handoff latency and disruption as much as possible. Our design is based on the Internet Protocol (IP) and is compatible with the Mobile IP standard (MIP). We also present simulation results showing that our handoff scheme is very fast to meet the requirements of an interactive communication session such as Internet telephony and avoiding packet loss

Efficient Micro-Mobility using Intra-domain Multicast-based Mechanisms (M&M)

One of the most important metrics in the design of IP mobility protocols is the handover performance. The current Mobile IP (MIP) standard has been shown to exhibit poor handover performance. Most other work attempts to modify MIP to slightly improve its efficiency, while others propose complex techniques to replace MIP. Rather than taking these approaches, we instead propose a new architecture for providing efficient and smooth handover, while being able to co-exist and inter-operate with other technologies. Specifically, we propose an intra-domain multicast-based mobility architecture, where a visiting mobile is assigned a multicast address to use while moving within a domain. Efficient handover is achieved using standard multicast join/prune mechanisms. Two approaches are proposed and contrasted. The first introduces the concept proxy-based mobility, while the other uses algorithmic mapping to obtain the multicast address of visiting mobiles. We show that the algorithmic mapping approach has several advantages over the proxy approach, and provide mechanisms to support it. Network simulation (using NS-2) is used to evaluate our scheme and compare it to other routing-based micro-mobility schemes - CIP and HAWAII. The proactive handover results show that both M&M and CIP shows low handoff delay and packet reordering depth as compared to HAWAII. The reason for M&M's comparable performance with CIP is that both use bi-cast in proactive handover. The M&M, however, handles multiple border routers in a domain, where CIP fails. We also provide a handover algorithm leveraging the proactive path setup capability of M&M, which is expected to outperform CIP in case of reactive handover.Comment: 12 pages, 11 figure

Adaptive Streaming in Mobile Network

Mobile ecommerce is immersed rapid familiar to other high-flying Internet markets. With the fast developing of wireless connections and Internet, electronic commerce more and more moves to mobile environment. Streaming, as a rapid growing application in Internet, will be more used in mobile ecommerce. In this paper, we’ll review the network protocol used in mobile ecommerce and streaming technology. An optimized architecture is given based on MPEG-4 and Mobile Ipv6. The core streaming protocol used in this architecture is RTSP/RTP proposed by IETF. This system gives one possible implementation of streaming over wireless network. Two key bottlenecks we found in this project are wireless bandwidth and mobile client power. To avoid the two problems, self-adaptive methodology is used. Let streaming application be adaptive to the wireless network environment to improve streaming performance

Implementation of MHMIP and Comparing the Performance With MIP and DHMIP in Mobile Networks

Managing the mobility efficiently in wireless networks causes critical issue, in order to support mobile users. To support global mobility in IP networks The Mobile Internet Protocol (MIP) has been proposed. The Hierarchical MIP (HMIP) and Dynamic HMIP (DHMIP) strategies are also proposed for providing high signaling delay. Our proposal approach “Multicast HMIP strategy” limits the registration processes in the GFAs. For high-mobility MTs, MHMIP provides lowest mobility signaling delay compared to the HMIP and DHMIP approaches. However, it is resource consuming strategy unless for frequent MT mobility. Hence, we propose an analytic model to evaluate the mean signaling delay and the mean bandwidth per call according to the type of MT mobility. In our analysis, the MHMIP gives the best performance among the DHMIP and MIP strategies in almost all the studied cases. The main contribution of this paper is to implement the MHMIP and provide the analytic model that allows the comparison of MIP, DHMIP and MHMIP mobility management approaches

A Framework of Cooperating Agents Hierarchies for Local-Area Mobility Support

Host mobility creates a routing problem in the Internet, where an IP address reflects the network\u27s point of attachment. Mobile IP, relying on a mapping between a home address and a care-of address, and a home registration process, is widely accepted as a solution for the host mobility problem in wide-area mobility scenarios. However, its home registration requirement, upon each change of point of attachment, makes it unsuitable to handle local-area mobility, resulting in large handoff latencies, increased packet loss, and disrupted services. In this dissertation, we introduce a local-area mobility support framework for IPv4 based on the deployment of multiple cooperating mobility agents hierarchies in the foreign domain. First, we introduce a hierarchy model offering a backward compatible mode to service legacy mobile hosts, unaware of local-area mobility extensions. Second, for intra-hierarchy handoffs, we identify several design deficiencies within the current Mobile IP hierarchy extension proposal, and present an enhanced regional registration framework for local handoffs that encompasses a replay protection identification value dissemination mechanism. In addition, we present two novel registration frameworks for home registrations involving local handoffs, in which we identify the dual nature of such registrations, and attempt to emphasize the local handoff aspect. One technique, maintains tunneling of data packets to the MH (Mobile Host) through an old path until a home registration reply is received to set up the new path. In contrast, the other technique adopts a more proactive bold approach in switching immediately to the new path resulting in a reduction of the handoff latency. Third, for inter-hierarchy handoffs, we present a scalable, configurable, and cooperation based framework between mobility agents hierarchies to reduce the handoffs latencies. An attempt is made to exploit the expected network proximity between hierarchies within the foreign domain, and maintain a mobile host\u27s home-registered care-of address unchanged while within the same foreign domain. In addition, the involved registration signaling design requires a reduced number of security associations between mobility agents belonging to different hierarchies, and copes with the fact that the mobile host\u27s home-registered care-of address might not be reachable

Using Link Layer Information to Enhance Mobile IP Handover Mechanism. An investigation in to the design, analysis and performance evaluation of the enhanced Mobile IP handover mechanism using link layer information schemes in the IP environment.

Mobile computing is becoming increasingly important, due to the rise in the number of portable computers and the desire to have continuous network connectivity to the Internet, irrespective of the physical location of the node. We have also seen a steady growth of the market for wireless communication devices. Such devices can only have the effect of increasing the options for making connections to the global Internet. The Internet infrastructure is built on top of a collection of protocols called the TCP/IP protocol suite. Transmission Control Protocol (TCP) and Internet Protocol (IP) are the core protocols in this suite. There are currently two standards: one to support the current IPv4 and one for the upcoming IPv6 [1]. IP requires the location of any node connected to the Internet to be uniquely identified by an assigned IP address. This raises one of the most important issues in mobility because, when a node moves to another physical location, it has to change its IP address. However, the higher-level protocols require the IP address of a node to be fixed for identifying connections. The Mobile Internet Protocol (Mobile IP) is an extension to the Internet Protocol proposed by the Internet Engineering Task Force (IETF) that addresses this issue. It enables mobile devices to stay connected to the Internet regardless of their locations, without changing their IP addresses and, therefore, an ongoing IP session will not be interrupted [2, 3, 4]. More precisely, Mobile IP is a standard protocol that builds on the Internet Protocol by making mobility transparent to applications and higher-level protocols like TCP. However, before Mobile IP can be broadly deployed, there are still several technical barriers, such as long handover periods and packet loss that have to be overcome, in addition to other technical obstacles, including handover performance, security issues and routing efficiency [7]. This study presents an investigation into developing new handover mechanisms based on link layer information in Mobile IP and fast handover in Mobile IPv6 environments. The main goal of the developed mechanisms is to improve the overall IP mobility performance by reducing packet loss, minimizing signalling overheads and reducing the handover processing time. These models include the development of a cross-layer handover scheme using link layer information and Mobile Node (MN) location information to improve the performance of the communication system by reducing transmission delay, packet loss and registration signalling overheads. Finally, the new schemes are developed, tested and validated through a set of experiments to demonstrate the relative merits and capabilities of these schemes